Department of Radiology, University "G. d'Annunzio" of Chieti, Chieti, Italy.
Department of Neuroscience, Imaging and Clinical Science, University "G. d'Annunzio" of Chieti, Chieti, Italy.
Neuroradiology. 2020 Sep;62(9):1105-1110. doi: 10.1007/s00234-020-02430-y. Epub 2020 Apr 18.
The head of the hippocampus (H) is classically described as having two to four digitations both in ex vivo specimens and in vivo MR coronal images. The aim of this study was to develop and evaluate a new MR-based classification of the anatomical variants of the hippocampal head in a large sample population of healthy subjects.
MR images of the brain of 238 young healthy subjects (138 men and 100 women; age range 18-39) were analyzed. The head of the H was identified on coronal reformatted 3D T1 weighted MR images. The frequencies were reported for hemisphere and sex. Inter-rater reliability was assessed.
Eight variants of the hippocampal head were described. Class 0 (11.4%) indicated a total absence of sulci. This class was further subdivided as follows: 0A (one digitation, 10.1%) and 0B (no digitations or "null variant", 1.3%). Class 1 (25.6%) presented a single sulcus and was further subdivided into four types according to the location and the width of the sulcus [1A (8.8%), 1B (12.8%), 1C (1.3%), and 1D (2.7%)]. Class 2 (63.0%, the most frequent and the classical variant) had two symmetrical sulci and three digitations. Statistically significant differences between the two hemispheres were observed only in women and overall. Differences in prevalence between sexes were not observed.
The large study population allowed the description of a novel morphological classification of the different anatomical variants of normal H in the coronal plane. This classification could reduce the risk of misinterpreting normal anatomical variants as pathological.
海马头部（H）的头部在离体标本和体内 MR 冠状图像中均经典地描述为具有两个到四个指状突起。本研究的目的是在大量健康受试者的样本中开发和评估一种新的基于 MR 的海马头部解剖变异分类方法。
分析了 238 名年轻健康受试者（138 名男性和 100 名女性；年龄范围 18-39 岁）的脑 MR 图像。在冠状位 3D T1 加权 MR 图像上识别 H 的头部。报告了半球和性别的频率。评估了观察者间的可靠性。
描述了 8 种海马头部变异。0 类（11.4%）表示没有沟裂。该类进一步细分为 0A（1 个指状突起，10.1%）和 0B（无指状突起或“空变体”，1.3%）。1 类（25.6%）表现为单个沟裂，并根据沟裂的位置和宽度进一步细分为 4 种类型[1A（8.8%）、1B（12.8%）、1C（1.3%）和 1D（2.7%）]。2 类（63.0%，最常见和经典的变异）有两个对称的沟裂和三个指状突起。仅在女性和总体上观察到两个半球之间的统计学显著差异。在性别之间未观察到流行率差异。
大量的研究人群允许在冠状面描述正常 H 的不同解剖变异的新形态分类。这种分类可以降低将正常解剖变异误诊为病理性的风险。
